Only English? I don't know. There are mixed groups in the Nagoya area though. One of my coworkers won the Japan pro-tournament last year and got a free trip to the finals in the US.Big Magic in Kamimaezu (just up the road from Joshin), or Yellow Submarine would be the best place to start. They have pretty big Magic groups playing there and some of the players will know some English, or will at least be better able to direct your friends.